Typical woman
Say they don't care, wait for others to choose and then pick the opposite
Or worse, wait until you are there and then start moaning that isn't what they wanted to do.
Splitting the bill is ok with me although it's probably best if we keep drinks out of it. Not really far if some people are ordering up bottles of wine etc and the tee-totallers have to chip in. Being able to order from the bar is all well and good, but once things are in full swing it wouldn't suprise me if people order something from the waiter
Regarding tips, usually what I do for group events is stick a couple of quid down, or say my share of the food comes to £17.60 or whatever, I'll stick £20 in including tip to keep things simple. As long as most people do similar there should be more than enough money for tips.
Looks like it could turn out quite an expensive weekend, having just extended my stay to 2 nights...